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51.
We develop analytical and numerical conditions to determine whether limit cycle oscillations synchronize in diffusively coupled systems. We examine two classes of systems: reaction–diffusion PDEs with Neumann boundary conditions, and compartmental ODEs, where compartments are interconnected through diffusion terms with adjacent compartments. In both cases the uncoupled dynamics are governed by a nonlinear system that admits an asymptotically stable limit cycle. We provide two-time scale averaging methods for certifying stability of spatially homogeneous time-periodic trajectories in the presence of sufficiently small or large diffusion and develop methods using the structured singular value for the case of intermediate diffusion. We highlight cases where diffusion stabilizes or destabilizes such trajectories. 相似文献
52.
Murat Durandurdu 《Journal of the American Ceramic Society》2016,99(5):1594-1600
The high‐pressure behavior of amorphous aluminum nitride is investigated for the first time by means of ab initio molecular dynamics simulations. It is found to undergo two successive first‐order phase transformations with the application of pressure. The first one is a polyamorphic phase transition in which the low‐density amorphous phase transforms into a high‐density amorphous phase having an average coordination number of about 4.6. The high‐density amorphous structure transforms back to a low‐coordinated amorphous network upon pressure release but its density is higher than that of the original low‐density amorphous phase. The second phase change is the crystallization of the high‐density amorphous state into a rocksalt structure. A careful analysis suggests that the hexagonal‐like nanoclusters presented in amorphous aluminum nitride prevent the formation of a very dense amorphous phase (about sixfold coordinated) during the first phase transition and they act as a nucleation center for the crystallization process. 相似文献
53.
54.
Murat Yusuf Sav Tansu Sav Elif Senocak Nadide Melike Sav 《Hemodialysis international. International Symposium on Home Hemodialysis》2014,18(4):725-729
Headache is one of the most frequently encountered neurological symptoms during hemodialysis. According to International Classification of Headache criteria dialysis‐related headache was defined as the headache occurring during hemodialysis with no specific characteristic. It resolves spontaneously within 72 hours after the hemodialysis session ends. There are few studies in the literature investigating the clinical features of dialysis headache. The pathophysiology of hemodialysis‐related headache is not known, but various triggering factors have been identified, including changes in blood pressure, serum sodium and magnesium levels during hemodialysis sessions, caffeine deprivation and stress. The aim of this article is to evaluate and analyze features of headache in patients undergoing hemodialysis. 相似文献
55.
Murat Uzam ZhiWu Li 《The International Journal of Advanced Manufacturing Technology》2014,74(1-4):503-507
In Hu (Transactions of the Institute of Measurement and Control 33:59–76, 2011), Petri nets are utilized to describe, analyse and control automated manufacturing systems (AMS). In order to suppress deadlock occurrences in AMS, a method to derive the bad markings iteratively using a mixed integer programming-based algorithm is proposed. To validate the effectiveness and efficiency of the proposed approach, two examples were demonstrated in Hu (Transactions of the Institute of Measurement and Control 33:59–76, 2011). This paper shows that the uncontrolled Petri net model in one of the examples is incorrect. It is also shown that the structural complexity of the computed monitors for both examples can be reduced with the same or more permissive system behaviours. 相似文献
56.
Deniz Ozdil Halil Murat Aydin 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2014,89(12):1793-1810
Recent decades have seen great advancements in medical research into materials, both natural and synthetic, that facilitate the repair and regeneration of compromised tissues through the delivery and support of cells and/or biomolecules. Biocompatible polymeric materials have become the most heavily investigated materials used for such purposes. Naturally‐occurring and synthetic polymers, including their various composites and blends, have been successful in a range of medical applications, proving to be particularly suitable for tissue engineering (TE) approaches. The increasing advances in polymeric biomaterial research combined with the developments in manufacturing techniques have expanded capabilities in tissue engineering and other medical applications of these materials. This review will present an overview of the major classes of polymeric biomaterials, highlight their key properties, advantages, limitations and discuss their applications. © 2014 Society of Chemical Industry 相似文献
57.
Mustafa Yıldırım Murat Tonaroğlu Murat E. Selçuk Cem Akgüner 《Bulletin of Engineering Geology and the Environment》2013,72(3-4):413-420
For over 50 years, the Upper Oligocene–Upper Miocene sedimentary sequence in Istanbul has been considered to be formed of two distinct sequences separated by an unconformity. However, recent field observations and an analysis of numerous borehole data indicate the Gürp?nar, Çukurçe?me and Güngören Formations are in fact a single sequence of alternating clay–sand/sandstone beds/lenses, here named the Avc?lar Formation. The Bak?rköy Formation, which is typically composed of carbonate rocks, conformably overlies the Avc?lar Formation. The paper provides the geotechnical parameters of the units within the Avc?lar Formation which it is hoped will facilitate selecting suitable geotechnical and engineering geological parameters to represent the deposits and minimize errors in the interpretation/evaluation of in-situ conditions. 相似文献
58.
Tan Fırat Eyüboğlu Murat Türkün Necdet Erdilek Mutlu Özcan 《Journal of Adhesion Science and Technology》2016,30(14):1574-1584
This study evaluated the long-term microleakage of access cavities conditioned with phosphoric acid and deproteinizing agents for root-canal-treated teeth using fluid filtration and microscopical analysis. Occlusal surfaces of extracted human mandibular premolars (N = 90) were removed leaving a 4 mm coronal length from the cemento-enamel junction. After root canal treatment, the specimens were randomly divided into four experimental groups (n = 21) and the remaining teeth were used for positive control group (n = 6): SB: 35% H3PO4 + Adper Single Bond 2; SSB: 35% H3PO4 + 5.25% NaOCl + 10% Sodium ascorbate (C6H7NaO6) + Adper Single Bond 2; XP: 35% H3PO4+XP Bond; SXP: 35% H3PO4+5.25% NaOCl + 10% Sodium ascorbate + XP Bond. All cavities were restored with a resin composite (Filtek Z250). After removing the root filling from the apical side, teeth were subjected to fluid filtration test for 1 week, 6 and 12 months followed by ×2500 thermocycling after 1st week and 6th months each. Data were analyzed using one-way ANOVA and Dunnet T3 tests (α = 0.05). SEM analyses were carried out after each microleakage evaluation in two random teeth from all groups. Microleakage values in groups SB and XP presented no significant difference in any of the evaluated period (p > 0.05). Microleakage results of SXP (0.01665) group showed significant difference compared to XP (0.03377) and SB (0.03049) groups after 12 months. SSB group (0.00901) showed significantly less microleakage among all other groups (0.01665–0.03377) (p < 0.05). Prior to endodontic treatment, in access cavities, acid etching with 35% H3PO4 followed by the application of NaOCl and sodium ascorbate completely destroyed the collagen layer, reducing the microleakage and resin–dentin interface degradation up to 12 months. 相似文献
59.
Polypyrrole/multi-walled carbon nanotube, poly(3,4-ethylenedioxythiophene)/multi-walled carbon nanotube and their nanocomposites P(EDOT-co-Py)/multi-walled carbon nanotube and P(EDOT-co-Py)/copper (II) oxide, (CuO) in the initial feed ratio of [EDOT]0/[Py]0 = 1/5 were electrosynthesized on glassy carbon electrode by cyclic voltammetric method. Their characterizations were performed by cyclic voltammetric, Fourier transform infrared-attenuated total reflectance, scanning electron microscopy, energy dispersion X-ray analysis, and electrochemical impedance spectroscopy. To the best of authors’ knowledge, the first report on polypyrrole/multi-walled carbon nanotube, PEDOT/multi-walled carbon nanotube, P(EDOT-co-Py)/multi-walled carbon nanotube and P(EDOT-co-Py)/CuO nanocomposite films were comparatively examined in 0.1 M NaClO4/CH3CN and in 0.1 M sodium dodecyl sulfate solutions. The highest specific capacitance for PEDOT/multi-walled carbon nanotube and polypyrrole/multi-walled carbon nanotube composite films were obtained as Csp = 306 mF × cm?2 for 3% multi-walled carbon nanotube and Csp = 804 mF × cm?2 for 1% multi-walled carbon nanotube, respectively. The highest specific capacitances were obtained as Csp = 27.40 mF × cm?2 and Csp = 26.90 mF × cm?2 for P(EDOT-co-Py)/multi-walled carbon nanotube includes the wt percent of 1% multi-walled carbon nanotube and P(EDOT-co-Py)/CuO includes the wt percent of 3% CuO, respectively. The Csp of P(EDOT-co-Py)/CNT composite films were calculated as 9.43 and 11.49 mF × cm?2 for 3 and 5% multi-walled carbon nanotube, respectively. In addition, The EIS results were simulated with the equivalent circuit model of Rs(Cdl1(R1(QR2)))(Cdl2R3). 相似文献
60.
Synthesis,characterization and,swelling behavior of semi‐IPN nanocomposite hydrogels of alginate with poly(N‐isopropylacrylamide) crosslinked by nanoclay 下载免费PDF全文
pH and temperature responsive nanocomposite hydrogels were synthesized with sodium alginate (NaAlg), N‐isopropylacrylamide (NIPA), and nanoclay. The structure, morphology, thermal behavior, and swelling and deswelling behaviors of the hydrogels were studied. The NaAlgm/PNIPA/Clayn hydrogels revealed a highly porous structure in which the pore sizes decreased and the amount of pores increased with increasing the nanoclay content in the hydrogels. PNIPA retained its own characteristics regardless of the amount of NaAlg and nanoclay. The effect of pH and nanoclay content on the swelling and effect of temperature on the deswelling behavior were investigated. The equilibrium swelling ratios of the nanocomposite hydrogels increased with increasing the pH from 2 to 6. The maximum swelling was attained at pH 6. Deswelling increased with increasing the nanoclay content in the hydrogels. The hydrogels were found to be pH and temperature responsive. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43222. 相似文献